I had one of those ‘you’re a linguist, let me ask you some grammar questions’ conversations while I was on fieldwork last year. This one I meant to report at the time but the post got overtaken by ‘events’, but even three months later it’s a good story.
The conversation went something like this. M stands for Me; I stands for my Interlocutor [not his real name].
I: If you’re a linguist, you must know heaps about grammar and the right way to talk, so can I ask you some things?
M: OK … <with more than a little dread in my voice> but I don’t study English so I might not be able to help.
I: There are a few things that really bug me. What’s the rule for when you say a and when you say an?
M: It’s an if the word starts with a vowel sound, and a if it’s a consonant sound. So it’s an apple but a fish.
I: A ha! But there are exceptions, right?
M: Well, most of the ‘exceptions’ I can think of are spelling exceptions. So, we say an honour, not a honour, but that’s because we don’t say the ‘h’ in honour, and so in speaking-terms it starts with a vowel. In the other direction, a union is spelled with a vowel but union starts with a j- sound, and the sound is a consonant.
I: But this h-thing isn’t right either. Haitch starts with a h- sound but people say an haitch. So they’re wrong! It should be a haitch-two-oh molecule, not an haitch-two-oh.
M: But in that case, it’s only one dialect of <Australian> English that says haitch. Most of the rest of Australia says aitch, and so in that case, using an is automatic.
A long argument then followed, including me and a bunch of doctors, about the pronunciation of h. Australianist readers will recognise a shibboleth of Catholic education in Australia, but what intrigued me most about all this is that my Interlocutor hadn’t noticed that most of the speakers he’d come into contact with didn’t say haitch-two-oh.